Within the framework of automatic braking, a function termed BTV (for “Brake-To-Vacate”) is known, the objective of which is to compute a controlled deceleration which will allow the airplane (rolling on a runway during landing) to stop automatically, level with an exit of the runway.
In particular, devices for automatic control of the deceleration of an airplane in the rollout phase which implement such a BTV function are known through documents FR-2 817 979 and FR-2 857 468. These devices allow the crew of the airplane to select an exit taxiway on the landing runway and to manage automatically and optimally (aid to the selection of a realistic exit taxiway compatible with known landing performance, minimization of runway occupation time, minimization of the necessary braking energy, improvement of comfort) the deceleration of the airplane during rollout on landing until the selected exit taxiway is attained. Consequently, under normal operational conditions, optimal attainment of this exit taxiway is guaranteed by virtue of these usual devices.
The computation of the aforementioned controlled deceleration is based mainly on the ground speed of the airplane and on the distances of the airplane and of the exit (selected by the pilot) with respect to the threshold of the runway.